We introduce the "Supersonic Project," aimed at investigating the effects of the supersonic relative velocity between dark matter (DM) and baryons at high redshift using a combination of analytical calculations and cosmological simulations. In this paper, we study the effect of this stream velocity on the angular momentum of the first structures in the early Universe using simulations. We focus on DM haloes and their gas component as well as the recently predicted supersonically-induced gas objects (SIGOs) that arise as a result of the stream velocity phase shift. We find that the spin parameter of the gas component in these first haloes is increased with the stream velocity. Moreover, we find that when the stream velocity is taken into account, the angular momentum vectors of the DM component and the gas component are typically misaligned and this misalignment angle has a nearly isotropic distribution. The spin parameter value of the gas component is higher than in the no stream velocity case, which even in the absence of cooling, may result in more prolate objects. We also generalize the spin parameter to the SIGOs and find that they typically have a larger spin parameter with respect to their dark matter counterparts and that there is no correlation of the spin parameter and the prolateness of such structures. We speculate that SIGOs may be observed as very low luminosity objects in the early Universe and may serve as potential progenitors of Little Blue Dot-like systems.
The Supersonic Project: SIGOs, a Proposed Progenitor to Globular Clusters, and their Connections to Gravitational Wave Anisotropies
超音速感生气体天体（英语：Supersonically Induced Gas Objects，缩写为SIRST）是一种几乎没有暗物质成分的结构，被预测存在于宇宙中重子和暗物质在复合时具有较大相对速度的区域。它们被认为是现今球状星团的祖先。使用模拟，SITERS已经研究了小尺度（约2百万秒差距），这些相对速度是相干的。然而，它是具有挑战性的，研究SITERS使用模拟在大尺度上，由于不同的相对速度在尺度大于几个百万分之一秒差距。在这里，我们研究SIGO丰度半解析：使用微扰理论，我们预测的数密度SIGO解析，并比较这些结果的小盒子数值模拟。我们使用的数值和分析计算之间的协议外推的大规模变化的SIGO丰度在不同的流速。因此，我们预测类似的大尺度变化的对象与高气体密度的再电离之前，可能会观察到的JWST。如果SIBs确实是球状星团的祖先，那么我们预计在大尺度上球状星团丰度也会有类似的变化。值得注意的是，我们发现SIGO的预期数量密度与观察到的球状星团数量密度一致。作为一个概念的证明，因为球状星团被认为是自然形成的网站引力波源从双黑洞（BBH）合并，我们表明，SITERS应该印上的引力波信号的天空中的各向异性，与SITERS的分布一致。
INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；INAF - Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Leibniz Institute for Astrophysics Potsdam (AIP)（波茨坦莱布尼茨天体物理研究所）；Center for Computational Astrophysics, Flatiron Institute（平托研究所计算天体物理学中心）；Departamento de Física, Universidad Técnica Federico Santa María（弗雷德里科·圣塔玛利亚技术大学物理系）；Millennium Nucleus for Galaxies (MINGAL)（星系千年核心）；DARK, Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所DARK研究中心）；Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Department of Physics and Astronomy "Augusto Righi", University of Bologna（博洛尼亚大学奥古斯托·里吉物理与天文学系）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；University Observatory, LMU Faculty of Physics（慕尼黑大学物理学院天文台）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文学研究所）
Laboratory rotational spectra of cyanocyclohexane and its siblings (1- and 4-cyanocyclohexene) using a compact CP-FTMW spectrometer for interstellar detection
JWST Confirmation of a Runaway Supermassive Black Hole via its Supersonic Bow Shock
Yale University（耶鲁大学）；Dragonfly Focused Research Organization（龙卷风重点研究机构）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森尼天体物理中心）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；University of Toronto（多伦多大学）；Tel Aviv University（特拉维夫大学）；San José State University（圣何塞州立大学）；University of California Santa Cruz（加州大学圣克鲁兹分校）
Spectroscopic and physical parameters of Galactic O-type stars. II. Observational constraints on projected rotational and extra broadening velocities as a function of fundamental parameters and stellar evolution
A method to deconvolve stellar rotational velocities III. The probability distribution function via Maximum Likelihood utilizing Finite Distribution Mixtures
